#include <stdio.h>  
#include <string.h>  
void swap(char *, int, int);  
  
int main() {  
    char num[1005];  
    gets(num);  
    for (int i = 1; i < strlen(num); i++) {  
        for (int j = i; j >= 1 || num[j - 1] > num[j]; j--)  
            if (num[j] > num[j - 1])  
                swap(num, j, j - 1);  
    }  
    puts(num);  
    return 0;  
}  
  
void swap(char *pnum, int i, int j) {  
    char temp = *(pnum + i);  
    *(pnum + i) = *(pnum + j);  
    *(pnum + j) = temp;  
}